Forest fires in mountain Pribaykalie

The formation and current state of forests in this region is closely related to forest fires that regularly occur throughout its territory. The fire hazard of the main forest types has been investigated for all high-altitude-zone vegetation complexes in different parts of the Baikal region. The high fire hazard of forest areas is due to the absolute domination of fire hazardous types of light coniferous stands in their composition and a specific climate with long spring-summer droughts. The most intense situations are observed in especially dry years of climatic cycles, with forest pyrogenic anomalies, when the fire element spreads over the main landscapes simultaneously in several natural regions. Such cataclysms were observed by the author at the very beginning of the study of the problem, during the aerial monitoring of the Baikal forests in the 1960s, when their fire protection was still in an extensive state due to the priority of intensification of logging. Constructive changes in forest management and forest fire protection required appropriate government decisions and fundamental scientific studies. The general management of the organization and maintenance of prospecting works was carried out by academician A. B. Zhukov. On his personal instructions, a route survey of probable objects for experimental research was undertaken in 1972 by a whole group of leading foresters of the V. N. Sukachev Institute Forest & Timber Siberian Branch USSR Academy of Sciences. The geomorphological profile of Khamar-Daban in the southern Baikal region has become a representative and stationary variant. The altitude range is 700–1300 m. The first group of experimental plots was established in the stands of the Siberian stone pine Pinus sibirica Du Tour, fir Abies Mill. and common pine Pinus L. on the northern mega-slope. On the axial part of the ridge, the objects of stationary research were stands of the Siberian stone pine and fir. In the light-coniferous belt on the southern mega-slope, the dynamics of fire hazard in pine and larch stands was studied. Long-term pyrological studies were carried out at all sites using the method of N. P. Kurbatsky. He carried out the scientific supervision of the work, and also directly participated in their implementation at the experimental sites. The stands on the southern mega-slope of Khamar-Daban were distinguished by the longest duration of the fire hazardous state. On the northern megaslope and in the midlands, a moderate situation usually prevailed. These differences are quite adequate to the distribution of atmospheric precipitation along the profile. Differences in the amount of precipitation on the axial part of the ridge and on the southern megslope in spring and summer reached 2–3 times values, and even more in terms of snow reserves. The maximum duration of the fire hazard was recorded in pine forests on insolated slopes. Larch forests differ from pine forests in a relatively low fire hazard. A grass layer is developed there, which prevents the spread of fire during the active growing season. In spring, the differences in the fire hazard of pine and larch forests are less significant. Dark coniferous forests in the middle mountains are distinguished by the shortest duration of the fire hazardous state. However, it should be noted that there is a local peculiarity in the propagation of combustion with the vertical closeness of the canopy in the Siberian stone-fir stands, with the threat of a transition from a ground fire to a crown fire. The timing of the end of the fire hazardous season is naturally related to the geomorphology of the sites. The latest dates were observed in pine forests on the southern megaslope of Khamar-Daban. The dependence of the process of fire maturation in different types of forest on the dynamics of the complex meteorological indicator is traced. The applied significance of the obtained characteristics is due to the fact that each of the three groups of experimental sites is associated with a certain forestry area in the basin of the lake Baikal: Baikal, mountain-taiga and mountain-forest-steppe. The structure and reserves of the ground layer of combustible materials have been studied. The data obtained indicate that more intense fires are possible in the Baikal region compared to other regions of Southern Siberia. The secular periodicity of abnormal forest fire situations is analyzed in connection with the territorial geoclimatic picture at the beginning of the fire hazardous season. The early appearance of spring forest fires at the same time throughout the entire snowless territory of the region is a sure sign of high tension of the beginning fire hazardous season, as it was in 1965, 1969, 1987, 2003 and 2015. It should be noted that after the modernization of the forest complex in the lake Baikal, which followed the scientific developments of the Institute of Forest and Timber, by the 1980s, the situation with forest fires in the region had stabilized. In this regard, there were no obstacles for a positive decision to assign the lake Baikal to the World Natural Heritage Sites. Unfortunately, the subsequent liberal reforms had a destructive effect on the entire forest complex, especially on the fire protection of forests